We’ve noticed, since we began distributing OCCL’s insoluble sulfur products, that some customers are using Chinese manufactured material, due to its cheap price. We strongly believe that you should consider ChemSpec’s insoluble sulfur (DS OT 20 HD & DS OT 20 HS)–even if priced higher than the competition–because of our products’ quality. This really comes down to the old adage: you get what you pay for!

Generally speaking, to be used properly in commercial manufacturing, insoluble sulfur needs to have the following characteristics:

High Thermal Stability,

High Insoluble Sulfur Content,

Controlled fineness,

Absence of any hard particles,

Low ash Content, and

Absence of any foreign particles and low Iron Content.

The above is necessary to ensure that the material does not bloom , disperses well, and there is no ingress of undesired material inside the rubber compound.

You will notice with Chinese-manufactured Insoluble Sulfur–from any supplier–that several of these parameters are likely lacking. This is the reason that no Chinese suppliers presently have Global approvals from any of the major tire manufacturers (NOTE: our product does have global approvals from the international tire producers). The processes used by Chinese producers commonly have some very basic, but serious, production issues–namely the following:

1. Production technology that cannot attain the above-described desired production parameters;

2. Production technology that cannot assure stability in the production performance parameters;

3. Their production processes do not use high grade quality stainless steel, which causes high corrosion levels and increased iron content;

5. Manual handling during some important production steps, translating into improper ingress of foreign material (our supplier’s process is automated).

Oftentimes, these failures result in, over time, the Chinese material chemically changing back to straight sulfur. So this problem is amplified if a customer is purchasing this material and having it shipped from China to another continent (i.e. North America), where the product sits for several months before being placed into a recipe.

For any further inquiries, please reach-out to us at ChemSpecLtd.com (or your respective sales representative).